Operating Manual - MFA-8000 and MFA-6000 Power Amplifier

9.3Bridged Mono Operation

(Normal/bridging switch in, channel 1 input used, channel 1 level control used, BRIDGED output used)

10.DESIGN THEORY

The MFA Series amplifiers are based on a dual- monaural design with each channel being electrically and physically identical. This type of design improves audio performance by eliminating power supply interaction and crosstalk. Failure of one channel will not affect the other. Because each channel is physically independent and fully integrated onto its own modular assembly, servicing is sim- plified.

The output stages of the MFA amps use compli- mentary bipolar power transistors. Bipolar transistors were chosen for maximum power efficiency and greater output current capacity, both of which are particularly important in high-power, low-frequency applications. Like all other Ashly power amps, all power and gain stages are 100% discrete. In other words, there are no op-amps used within the power amp’s main signal path or feedback loop. This results in an exceptionally clean and well behaved output waveform (no glitching or ringing) in the presence of tran- sients or clipping.

All power supply high current paths are retained on each channel’s respective PC board, keeping wiring to a minimum. The power supply uses three DC voltage lev- els which are switched sequentially by ultrafast MOSFETs depending on the demands of the output voltage. This concept is employed for greater power efficiency and to reduce the AC power consumption.

Sophisticated power amp monitoring circuits de- tect any abnormal conditions which may cause damage to the amplifier or speakers. A highly accurate clip de- tector illuminates the CLIP LED at the onset of clipping. Further increases in signal level will activate a limiter circuit which prevents severe overload distortion from oc- curring. This limiter circuit illuminates the LIMIT LED when it becomes active, where the light intensity of the LED indicates the amount of signal attenuation.

Advanced thermal management circuitry senses temperature at four locations in the amp and adjusts fan speed accordingly. A THERMAL LED on each channel indicates an above normal operating temperature. The light intensity of this LED is an indication of the temperature above normal. If the internal temperature becomes excessive, the limiter circuit will attenuate the input signal until the amplifier returns to a normal

operating range. The amplifier’s output will automatically shut down in the event of a fault condition such as severe overheating, shorted output, DC voltage, or extreme high frequency energy. A PROTECT LED indicates when one or more of these abnormal conditions occur. Each channel’s limiting, thermal, and protection management functions are completely independent of the other channel.

The MFA Series amplifiers are equipped with the necessary circuitry for computer control and monitoring as this capability becomes available in the future.

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Ashly MFA-6000, MFA-8000 manual Bridged Mono Operation, Design Theory
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MFA-6000, MFA-8000 specifications

The Ashly MFA-8000 is a state-of-the-art audio amplifier designed for both professional and commercial audio applications. Renowned for its reliability, sound quality, and versatility, this amplifier is perfect for installation in concert halls, theaters, houses of worship, and various other venues that require robust audio performance.

One of the standout features of the MFA-8000 is its impressive power output. Delivering 800 watts per channel at 4 ohms, the amplifier is capable of driving demanding speaker systems with ease, ensuring that sound reproduction remains crisp and clear, even at high volumes. This power is complemented by a dynamic range that enhances the listening experience, making it suitable for music playback, public announcements, and other audio applications.

The MFA-8000 incorporates Class AB amplification technology, which is known for its low distortion and high linearity. This ensures that the audio signal remains faithful to the source material, providing an authentic listening experience. Additionally, the amplifier includes advanced protection circuits that safeguard against overloads, short circuits, and overheating, ensuring longevity and durability.

In terms of connectivity, the MFA-8000 offers a variety of input options, including XLR, 1/4" TRS, and RCA connectors, making it highly versatile and compatible with a wide range of audio sources. The rear panel features an intuitive layout that simplifies the connection process, allowing users to easily integrate the amplifier into existing audio setups.

Furthermore, the MFA-8000 is equipped with built-in signal processing capabilities, including adjustable crossover settings and EQ controls, allowing users to tailor the output to suit the specific acoustics of their venue. This adaptability makes it an excellent choice for installations where sound quality must be optimized for different settings or events.

Cooling is also a critical aspect of the MFA-8000’s design. The amplifier features a highly efficient cooling system with variable-speed fans that ensure the unit remains cool even during prolonged use, preventing thermal issues that could compromise performance.

Overall, the Ashly MFA-8000 is a powerful and reliable audio amplifier that combines advanced technologies with practical features, making it an ideal solution for a wide range of professional audio applications. Its robust construction, high-quality sound reproduction, and user-friendly design make it a valuable addition to any audio setup, ensuring that it meets the demands of both sound engineers and everyday users alike.
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